Spy says Krelmin gremlin could put the bite on Trump

US news website Mother Jones.com claimed the Kremlin has been cultivating Mr Trump for five years.

Mother Jones said Mr Trump "and his inner circle have accepted a regular flow of intelligence from the Kremlin, including on his Democratic and other political rivals”.

A former senior intelligence officer for a Western country told the site that he provided the FBI with infor mation that the Russian government had for years tried to co-opt and assist Mr Trump.

The FBI has not released any details.

Mrs Clinton's campaign says FBI director James Comey is applying a double standard when it comes to the presidential candidates.

On the weekend Mr Comey disclosed the FBI had newly discovered emails that may be relevant to the Clinton email investigation.

Clinton campaign manager Robby Mook cited a report from cable channel CNBC that said Mr Comey opposed releasing information close to election day about Russian interference in the US election.

The FBI declined to comment and Mr Mook called the report evidence of a "blatant double standard”.

Mother Jones reported that a memo as part of the former spy's work said: "Russian regime has been cultivating, supporting and assisting Trump for at least five years. Aim, endorsed by Putin, has been to encourage splits and divisions in Western alliance.”

It claimed Russian intelligence had "compromised” Mr Trump during his visits to Moscow and could "blackmail him”. It said Russian intelligence had compiled a dossier on Mrs Clinton.

However, the New York Times reports that while the FBI investigated a possible Russian role in the campaign, law enforcement officials say no investigation has so far found any link between Mr Trump and the Russian Government.

Earlier Mr Trump had predicted a tidal wave of migrants swamping the US if Mrs Clinton was elected.

"You could have 650 million people pour in and we do nothing about it. You triple the size of our country in a week,” he said.

In other election news, the head of Britain's MI5 has warned Russia has an increasingly aggressive approach to foreign policy, including propaganda, spying and cyber-attacks and seems to define itself by opposition to the West.